Math in English looks sharp for me

I've been learning English Math for kids to understand English logic. It's easy to get the meaning, and it's also often easy to understand the grammar, so I like to read it.

Recently I came across a math definition. It's about Perpendiculars in Math. The definition is, "at right angles to the horizon."

I think this definition is very concise and is a very English way of describing something.

I think that it would be able to be translated into Japanese like "水平線に対して、常に直角であること"(Always being a right angle against the horizontal line), yet the English definition is still more concise.